Application Crash — CraftedSignal Threat Feed

Sticky Notes & Color Widgets 1.4.2 Denial of Service Vulnerability (CVE-2021-47972)

hello@craftedsignal.io — Sat, 16 May 2026 16:21:17 +0000

Sticky Notes & Color Widgets 1.4.2 is susceptible to a denial-of-service (DoS) vulnerability. This vulnerability, identified as CVE-2021-47972, allows a remote, unauthenticated attacker to crash the application. By crafting notes containing excessively long character strings, an attacker can exhaust the application’s resources, leading to a crash and rendering the application unresponsive. The vulnerability was reported on May 16, 2026.

Attack Chain

Attacker opens the Sticky Notes & Color Widgets application.
Attacker creates a new note within the application.
Attacker pastes a large payload of repeated characters (an excessively long string) into the note’s text field.
The application attempts to allocate memory to store the overly large note content.
Due to the excessive size of the string, the memory allocation fails or consumes excessive resources.
The application becomes unresponsive as it struggles to process the oversized data.
The application crashes due to resource exhaustion or a memory allocation error.
The Sticky Notes & Color Widgets application is no longer available to the user until restarted.

Impact

Successful exploitation of this vulnerability results in a denial-of-service condition. The Sticky Notes & Color Widgets application becomes unusable, disrupting the user’s workflow. While the vulnerability does not lead to data loss or compromise of the system, it can cause inconvenience and temporary loss of productivity. The CVSS v3.1 base score for this vulnerability is 7.5, indicating a high impact on availability.

Recommendation

Monitor application logs for unusual memory allocation patterns, which could indicate exploitation attempts.
Implement input validation to limit the size of notes created within the application to mitigate CVE-2021-47972.
Deploy the Sigma rule to identify potential attempts to exploit the denial-of-service vulnerability.
Consider contacting the vendor for a patch or update addressing CVE-2021-47972.

Macaron Notes 5.5 Denial of Service Vulnerability (CVE-2021-47970)

hello@craftedsignal.io — Sat, 16 May 2026 16:20:48 +0000

Macaron Notes 5.5 is susceptible to a denial-of-service (DoS) vulnerability (CVE-2021-47970) that can be triggered by an attacker providing an excessively long string of characters within a note. This can be achieved by generating a string of approximately 350,000 repeated characters and pasting it into a note field within the application. Successful exploitation leads to the application crashing and becoming unresponsive. This vulnerability poses a risk to users who rely on the availability and stability of Macaron Notes for their note-taking and organizational needs. By exploiting this vulnerability, an attacker can disrupt the normal functioning of the application, potentially leading to data loss or user frustration.

Attack Chain

An attacker identifies a target user or system running Macaron Notes 5.5.
The attacker crafts a malicious payload consisting of a very long string (e.g., 350,000 characters).
The attacker opens the Macaron Notes application.
The attacker creates a new note or modifies an existing note.
The attacker pastes the oversized string into the note’s content field.
The application attempts to process the excessively large input.
Due to insufficient input validation or memory allocation, the application becomes unresponsive.
The Macaron Notes application crashes, resulting in a denial of service.

Impact

The successful exploitation of CVE-2021-47970 results in a denial-of-service condition, causing the Macaron Notes 5.5 application to crash. This can lead to data loss if users have unsaved changes. The impact is primarily on individual users of the application who may experience disruption and inconvenience. The vulnerability is rated as HIGH severity with a CVSS v3.1 score of 7.5.

Recommendation

Deploy the Sigma rule “Detect Macaron Notes Long String DoS Attempt” to detect potential attempts to exploit CVE-2021-47970 in application logs.
Monitor application logs for unusually long strings being processed by Macaron Notes using the “Detect Macaron Notes Crash” Sigma rule, and investigate any anomalies.
Consider contacting the vendor for a patch or upgrade to a version of Macaron Notes that addresses CVE-2021-47970.

Color Notes 1.4 Denial-of-Service Vulnerability (CVE-2021-47969)

hello@craftedsignal.io — Sat, 16 May 2026 16:20:34 +0000

Color Notes 1.4 is susceptible to a denial-of-service vulnerability (CVE-2021-47969). This flaw allows an attacker to crash the application by exploiting its handling of extremely large text inputs. The attack involves crafting a payload consisting of a long, repeated character string, specifically a string of 350,000 characters. By pasting this oversized payload twice into a new note within the application, an attacker can overwhelm the application’s resources, leading to a crash and rendering it temporarily unavailable. This vulnerability poses a threat to user productivity and data integrity.

Attack Chain

Attacker crafts a malicious payload consisting of a repeated character string of approximately 350,000 characters.
Attacker opens the Color Notes 1.4 application.
Attacker creates a new note within the application.
Attacker pastes the crafted 350,000-character string into the new note field.
Attacker pastes the same 350,000-character string again into the same note field.
The application attempts to process the excessively large text input.
The application’s resources are exhausted due to the oversized payload.
The application becomes unresponsive and crashes, resulting in a denial-of-service condition.

Impact

The successful exploitation of this denial-of-service vulnerability results in the Color Notes 1.4 application becoming unresponsive and crashing. Users will be unable to access their notes and may experience data loss or corruption if the application does not properly save data before crashing. While the scope of this vulnerability is limited to a single application, it can still disrupt workflows and cause frustration for affected users. The number of victims is dependent on the usage of Color Notes 1.4.

Recommendation

Monitor for process crashes of Color Notes 1.4 using the process_creation rule included in this brief.
Implement input validation and sanitization measures within Color Notes to limit the size of text inputs accepted by the application to prevent similar denial-of-service attacks.
Consider deploying the file_event rule included in this brief to monitor for the creation of excessively large text files which could be used as part of the attack.